Add Milestones 1 & 2: full-stack POS foundation with admin UI

- Node/Express/TypeScript API under /api/v1 with JWT auth (login, refresh, logout, /me)
- Prisma schema: vendors, users, roles, products, categories, taxes, transactions
- SQLite for local dev; Postgres via docker-compose for production
- Full CRUD routes for vendors, users, categories, taxes, products with Zod validation and RBAC
- Paginated list endpoints scoped per vendor; refresh token rotation
- React/TypeScript admin SPA (Vite): login, protected routing, sidebar layout
- Pages: Dashboard, Catalog (tabbed Products/Categories/Taxes), Users, Vendor Settings
- Shared UI: Table, Modal, FormField, Btn, PageHeader components
- Multi-stage Dockerfile; docker-compose with Postgres healthcheck
- Seed script with demo vendor and owner account
- INSTRUCTIONS.md, ROADMAP.md, .claude/launch.json for dev server config

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/node_modules/postcss/lib/postcss.mjs

@@ -0,0 +1,30 @@
+import postcss from './postcss.js'
+
+export default postcss
+
+export const stringify = postcss.stringify
+export const fromJSON = postcss.fromJSON
+export const plugin = postcss.plugin
+export const parse = postcss.parse
+export const list = postcss.list
+
+export const document = postcss.document
+export const comment = postcss.comment
+export const atRule = postcss.atRule
+export const rule = postcss.rule
+export const decl = postcss.decl
+export const root = postcss.root
+
+export const CssSyntaxError = postcss.CssSyntaxError
+export const Declaration = postcss.Declaration
+export const Container = postcss.Container
+export const Processor = postcss.Processor
+export const Document = postcss.Document
+export const Comment = postcss.Comment
+export const Warning = postcss.Warning
+export const AtRule = postcss.AtRule
+export const Result = postcss.Result
+export const Input = postcss.Input
+export const Rule = postcss.Rule
+export const Root = postcss.Root
+export const Node = postcss.Node